October 22, 2015

Could We Have a Natural Control for Horrible Cheatgrass?

Now, some 65 years after famed naturalist Aldo Leopold summed up the
general consensus in the battle against cheatgrass as hopeless, there
might be hope.

"We're in a better position to fight back than we have
ever been," said Susan Meyer, a U.S. Forest Service research ecologist
working with fungus at the Shrub Sciences Laboratory in Provo, Utah.

Why is cheatgrass a Bad Thing?

• It comes up early in the spring. At that point it is soft and green. It looks good to eat, hence the "cheat" part.

• But very soon it sets its seeds in horrible, prickly awns that hurt grazing animals' mouths, puncture people's shoes and socks, catch in other animals' coats, and spread wherever they are carried.

In addition to being a wildfire threat and an ecological problem,
cheatgrass can harm animals. Its stiff, spiny seedheads, called awns,
can work their way into the ears, eyes or mouths of everything from cats
to cattle.

The keys to cheatgrass spread are its short life
cycle and prolific seed production. Because cheatgrass stands dry out by
mid-June, fires are more likely to occur earlier in the season. These
mid-summer fires are tough on native forbs and grasses.

Cheatgrass seeds
drop prior to fires and will germinate with fall precipitation. This
gives rise to dense, continuous stands that make additional fire
ignition and spread more likely. Fire return intervals have gone from
between 60–110 years in sagebrush-dominated systems to less than 5 years
under cheatgrass dominance. With every reoccurring fire, cheatgrass
becomes more dominant and expands its range further.

• It has damged the West by reducing feed for both wildlife (elk, deer, pronghorn antelope) and domestic animals:

“Cheatgrass has probably created the greatest ecological
change in the western United States of anything we’ve ever
done,” said Steve Monsen, a retired Forest Service botanist
in Utah who conducts research for the agency.

It can be grazed when young and green, but unlike native perennial grasses, it does not "cure" on the stem for winter consumption.

On my own little patch of Colorado, I watched cheatgrass move from roadsides, seemingly leap over healthier pastures, and appear in groves of pines trees.

So what Is the new development?

There are pesticides that work against cheatgrass, but the invasion is too big to spray it all. Susan Mayer and others are looking at bacteria instead:

Meyer and Ann Kennedy, a scientist in
Washington state working with bacteria, are drawing attention from top
land managers and policy makers — and research money — after showing
that the seemingly invincible cheatgrass might have an Achilles' heel.

"We've found several organisms that are really good at colonizing the
root of the seed, and reducing the elongation of that root," said
Kennedy, who works at Washington State University. "Then that cheatgrass
is less competitive the next spring."